Hi sneather, so in order to repair this I drew in this new curve shown here:



Then I did an untrim and a retrim of both of the surfaces to either side of that area that previously had a large gap in the trim boundary, that's how I got the fixed model version which I have attached. Before doing the untrim sometimes you also need to duplicate some edge curves (by selecting then copy/paste) if they are ones you need for retrimming and they are going to get erased by the untrim.

- Michael